The goal of this project is to produce comprehensive, high-definition maps of mouse regulatory DNA marked by DNaseI hypersensitive sites to parallel the human catalogue currently under production by the ENCODE Project. Digital DNaseI technology enables efficient genome-wide mapping of accessible chromatin and DNaseI hypersensitive sites. The core regions of DNaseI hypersensitive sites are constitutively populated by regulatory factor binding sites, the nucleotide-resolution footprints of which may be systematically exposed on a genome-wide scale by ultra-deep sequencing. DNaseI hypersensitive sites exhibit marked cell-type variability;accordingly, production of a comprehensive catalog will require surveying a wide range of cell types. Cell types targeted under this proposal include murine analogues of the ENCODE Tier 1 and Tier 2 common reference cell lines;a broad spectrum of primary adult tissues;embryonic stem cells;and sentinel tissues amenable to sequential temporal profiling during development. The production of a parallel, high-quality, high-resolution compendium of mouse regulatory DNA will greatly enhance the value of the human ENCODE project and will provide a rich independent and unique resource for evolutionary, functional, and model organism genomics. PUBLIC HEALTH RELEVANCE: Relevance to Public Health Understanding the genetic basis of human disease requires detailed knowledge of the functional elements of the human genome which may be subject to polymorphism. The ENCODE Project seeks to identify all of the functional elements in the human genome, and present project seeks to greatly increase the value of the ENCODE data by providing a parallel catalogue of regulatory DNA in the mouse genome. This project is therefore expected to provide key insights into the importance of elements in the human genome, and to provide an unprecedented resource for rational functional modeling of human disease in the mouse.